I'm using UINavigationController. How do I stop (call the invalidate method) on my timer when the user hits the back button.
I presume you can use viewWillDisappear method to detect indirectly when back is pressed and invalidate your timer
//Put this viewDidLoad and make sure you have a back.png that mimics back button
UIImage *buttonImage = [UIImage imageNamed:#"back.png"];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:self action:#selector(backPressed:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = customBarItem;
- (void)backPressed:(id)sender {
[yourTimer invalidate];
}
If the timer is running in another class use NSNotificationCenter to post a notification in backPressed Method
See NSNotification Center example here NSNotification Tutorial
Related
I have been trying to write a program in which a button appears after a timer fires. The timer is working properly, as is the firing event (I have tested this with different events). However, the button I am making appear is not showing up. Also, I would like the button background image to change when the button is pressed and held. I have tried making the button just have a background color instead of an image, but that does not work either. The code is located in the Timer selector within the view controller Any help is appreciated. Thanks!
- (void)timerFireMethod:(NSTimer *)timer
{
Button = [UIButton buttonWithType:UIButtonTypeCustom];
Button.center = CGPointMake(self.view.frame.size.width/2, self.view.frame.size.height/2);
[Button setBackgroundImage:[UIImage imageNamed:#"buttonUnheldBGImage"]
forState:UIControlStateNormal];
[Button setBackgroundImage:[UIImage imageNamed:#"buttonHeldBGImage"]
forState:UIControlStateHighlighted];
[Button setTitle:#"Press and Hold" forState:UIControlStateNormal];
[Button addTarget:self action:#selector(aSelector:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:Button];
}
The timer class that calls this is:
- (void)timer
{
globalTimer = [NSTimer scheduledTimerWithTimeInterval:5
target:self
selector:#selector(timerFireMethod:)
userInfo:Nil
repeats:NO];
}
globalTimer is a global NSTimer
You have set the center of the button but you also need the frame of it, i believe that the button is showing now but his frame is (0,0).
You have to set a size to your button as well. If you want it at the center of your super view just do :
CGRect buttonFrame = CGRectMake(self.view.frame.size.width/2-100,self.view.frame.size.height/2-100, 200,200);
Button.frame = buttonFrame;
The center property is essentialy used for UI Element that already have a size.
Just replace your first 2 lines,
UIButton * Button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
Button.frame = CGRectMake(20, 200, 200, 200);
backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[backButton addTarget:self action:#selector(gotoAmphorasViewController) forControlEvents:UIControlEventTouchUpInside];
[backButton setFrame:CGRectMake(0.0f,0.0f, 44,44)];
The problem i am facing is that though the button dimensions are44*44, wherever i tap anywhere around it, the the button action is fired.
Please try the bellow code : its working properly
- (void)viewDidLoad {
[super viewDidLoad];
UIImage *buttonImage = [UIImage imageNamed:#"back.png"];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:self action:#selector(back) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = customBarItem;
[customBarItem release];
}
-(void)back {
[self.navigationController popViewControllerAnimated:YES];
}
Its not a bug. It is a default behaviour. In iPhone, for navigation bar buttons the touch detection is little more expanded rather than its frame. Just have a look on any other application. Everywhere the button get fired if we tap nearer but outside its frame.
It's the intended behaviour, if you really want to limit the area of the touch, you can wrap the button inside a UIView:
UIView *buttonContainer = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 44, 44)];
[buttonContainer addSubview:button];
_barButton = [[UIBarButtonItem alloc] initWithCustomView:buttonContainer];
I want to show custom navigation bar back button. I want to show only image on it. I want to use this button in whole app also dont want to create this button in each file. How can i??
Here is my code:
// Set the custom back button
UIImage *buttonImage = [UIImage imageNamed:#"back_arrow.png"];
//create the button and assign the image
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
//set the frame of the button to the size of the image (see note below)
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:self action:#selector(popViewControllerAnimated:) forControlEvents:UIControlEventTouchUpInside];
//create a UIBarButtonItem with the button as a custom view
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = customBarItem;
but this is showing on current page only.
Another code:
[[UIBarButtonItem appearance] setBackButtonBackgroundImage:[UIImage imageNamed:#"back_arrow.png"] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
Using this code back button image is showing in whole app. But the text "Back" is also showing. How can i solve this problem.
Thanks in advance.
I've used a category in the past to do this.
Create a category on UIBarButtonItem called +projectButtons (or something).
Then you can have a function like...
+ (UIBarButtonItem)backArrowButtonWithTarget:(id)target action:(SEL)action
{
UIImage *buttonImage = [UIImage imageNamed:#"back_arrow.png"];
//create the button and assign the image
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
//set the frame of the button to the size of the image (see note below)
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
//create a UIBarButtonItem with the button as a custom view
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
return customBarItem;
}
Then add it to you navigation bar like so...
self.navigationItem.leftBarButtonItem = [UIBarButtonItem backArrowButtonWithTarget:self action:#selector(popViewControllerAnimated:)];
This means you only need one line of code to create it but you still get the customisation of the target and action in each VC that you use it in. If you decide to change the look of the button then it's all done in one place.
I cannot figure out how to disable the back-button animation that occurs in the navigation bar when switching from a tableview to a standard view (when a cell is selected). There is no obvious line of code that enabled animation to begin with. Here it is in gif-form:
The navigation buttons in the Facebook app do not animate, so it is possible.
It may be relevant to mention that I am using the ViewDeck library to create the Facebook-like tableView menu, i.e. swipe to the right to expose a table.
EDIT: solution is based on Hesham Abd-Elmegid's answer but modified to use a custom image...
UIImage *settingsImage = [UIImage imageNamed:#"back_button#2x.png"];
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
backButton.frame = CGRectMake(280.0, 10.0, 29.0, 29.0);
[backButton setBackgroundImage:settingsImage forState:UIControlStateNormal];
backButton.frame = CGRectMake(0, 0, 50, 30);
[backButton addTarget:self action:#selector(goBack) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
self.navigationItem.leftBarButtonItem = customBarItem;
If you set a custom UIBarButtonItem as a left navigation item (instead of standard back button item), it will fade instead of slide in, just like in Facebook's app. Just create a simple method that will replace back button functionality by calling popViewControllerAnimated: on the navigation controller in which your detail view controller is contained.
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:#"Back" style:UIBarButtonItemStyleBordered target:self action:#selector(goBack)] autorelease];
}
- (void)goBack
{
[self.navigationController popViewControllerAnimated:YES];
}
Note: UIBarButtonItem can also be set up with an image using initWithImage:style:target:action: method.
You could replace the back button with a custom UIButton. That way it won't animate on transition.
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:#"Back" forState:UIControlStateNormal];
backButton.frame = CGRectMake(0, 0, 50, 30);
[backButton addTarget:self action:#selector(onBack) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
self.navigationItem.leftBarButtonItem = customBarItem;
[customBarItem release];
You will have to find a PNG for the arrow shape of the back button though.
Hey, I've written a class (A) which inherits some functionality including an implementation of a navigation button. Class A has both a view and edit mode, I want to only show the button when am in edit mode. So far I've not been able to remove this button and I don't really want to create to another class just for edit.
Also other classes inherit this functionality so I don't really want to be messing about with parent.
The code that I use to create the button is below:
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *buttonImage = [UIImage imageNamed:#"button.png"];
[button addTarget:self
action:#selector(buttonPressed:)
forControlEvents:UIControlEventTouchUpInside];
button.bounds = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button setBackgroundImage:buttonImage forState:UIControlStateNormal];
[button setTitle:NSLocalizedString(#"BUTTON", #"")
forState:UIControlStateNormal];
LPRBSLabel *buttonLabel = [[LPRBSLabel alloc] initWithStyle:UICustomeButtonTitle];
[button setTitleEdgeInsets:UIEdgeInsetsMake(0.0, 0.0, -5.0, 0.0)];
button.titleLabel.font = buttonLabel.font;
[button setTitleColor:buttonLabel.textColor forState:UIControlStateNormal];
[buttonLabel release];
UIBarButtonItem *barLeftInfoButton = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = barLeftInfoButton;
[barLeftInfoButton release];
I managed to solve it using:
self.navigationItem.leftBarButtonItem = nil;
I had a mind freeze and was using the above statement before the button had actually when created :-(
It would be easier to set the NavigationItem's property "hidesBackButton" to yes:
http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UINavigationItem_Class/Reference/UINavigationItem.html#//apple_ref/occ/cl/UINavigationItem
Another option to consider is to disable the button until you want it to function. It will be visible, but dimmed.
self.navigationItem.leftBarButtonItem.enabled = NO;
To Remove Button from navigation bar just assign tag to button and write a below code
[[self.navigationController.navigationBar viewWithTag:0106] removeFromSuperview];